Reproducibility and Convergent Validity of the Sitting-Rising Test in People With Multiple Sclerosis

ObjectiveTo evaluate the test-retest reproducibility and convergent validity of the sitting-rising test (SRT) in people with multiple sclerosis (PwMS).DesignObservational study comprising a test-retest design.SettingMultiple Sclerosis Center, Rehabilitation Hospital at Sheba Medical Center, Tel-Hashomer, Israel.ParticipantsA total of 50 PwMS (32 women, 18 men, N=50), mean age 44.8±7.6 years and mean disease duration of 13.8±8.5 years since diagnosis, were enrolled in the study. The median Expanded Disability Status Scale score was 4.5, indicating a mild-moderate neurologic disability.InterventionsNot applicable.Main Outcome MeasuresSRT, posturography measures, 10-repetion sit-to-stand test (10STS), timed Up and Go (TUG) test, hand grip strength, strength of hip flexion/extension/abduction, knee flexion/extension, and Fall Status Questionnaire.ResultsThe intraclass correlation coefficient value for the intrarater test-retest reproducibility (7- to 10-day interval between tests) of the SRT test, was 0.931 (95% confidence interval, 0.796-0.977). Strong correlations were found between the SRT, TUG test (ρ=−0.709), and 10STS (ρ=−0.719), and moderate correlations were found between the SRT and postural control measures (ρ∼0.4). Moderate correlations were found between the SRT and the hip and knee strength (combined) of the weaker limb (ρ=0.344). No differences were found in the SRT score between fallers and nonfallers.ConclusionsThe current study supports the convergent validity and test-retest reproducibility of the SRT in PwMS.     

哌甲酯调节正常成年人大脑对go/no-go任务的反应

目的 通过比较正常被试服用哌甲酯与安慰剂后执行go/no-go任务时脑区激活的差异,探明5-羟色胺(5-HT)系统在哌甲酯调节动作抑制中的作用.方法 药物(哌甲酯,安慰剂)和任务(go组块,nogo组块)两因素被试内设计.18名男性健康大学生志愿者,服用哌甲酯(20 mg)或安慰剂(维生素B6 20 mg)后,分别在进行功能磁共振(fMRI)扫描的同时执行组块设计的go/no-go任务.结果 哌甲酯可减少眶-前额皮质的激活程度,增加小脑、海马的激活.任务主效应主要体现在与运动有关的脑区,如运动区、丘脑、壳核等.同时,哌甲酯可增强中缝核在抑制任务时的反应,与之有相同激活模式的还有苍白球及左侧小脑.激活阈限均为P＜0.01,未校正,连续体素＞20个.结论 哌甲酯可能通过5-HT系统发挥作用.     

Functional brain changes in early Parkinson's disease during motor response and motor inhibition

Motor impairment represents the main clinical feature of Parkinson's disease (PD). Cognitive deficits are also frequently observed in patients with PD, with a prominent involvement of executive functions and visuo-spatial abilities. We used event-related functional MRI (fMRI) and a paradigm based on visual attention and motor inhibition (Go/NoGO-task) to investigate brain activations in 13 patients with early PD in comparison with 11 healthy controls. The two groups did not report behavioural differences in task performance. During motor inhibition (NoGO-effect), PD patients compared to controls showed an increased activation in the prefrontal cortex and in the basal ganglia. They also showed a reduced and less coherent hemodynamic response in the occipital cortex. These results indicate that specific cortico-subcortical functional changes, involving not only the fronto-striatal network but also the temporal-occipital cortex, are already present in patients with early PD and no clinical evidence of cognitive impairment. We discuss our findings in terms of compensatory mechanisms (fronto-striatal changes) and preclinical signs of visuo-perceptual deficits and visual hallucinations.     

Lesion neuroanatomy of the Sustained Attention to Response task

The Sustained Attention to Response task is a classical neuropsychological test that has been used by many centres to characterize the attentional deficits in traumatic brain injury, ADHD, autism and other disorders. During the SART a random series of digits 1–9 is presented repeatedly and subjects have to respond to each digit (go trial) except the digit ‘3’ (no-go trial). Using voxel-based lesion symptom mapping (VLSM) in a consecutive series of 44 ischemic unifocal non-lacunar hemispheric stroke patients we determined the neuroanatomy of 4 SART parameters: commission and omission error rate, reaction time variability and post-error slowing. Lesions of the right inferior frontal gyrus significantly increased commission error rate. Lesions of the middle third of the right inferior frontal sulcus (IFS) reduced post-error slowing, a measure of how well subjects can utilize errors to adjust cognitive resource allocation. Omissions and reaction time variability had less localising value in our sample. To conclude, commission errors and post-error slowing in the SART mainly probe right inferior frontal integrity.     

内、外群体态度与士兵内隐集体自尊效应

目的:考察士兵针对内群体与外群体的评价性态度,验证是否存在内隐集体自尊效应.方法:通过Go/No-go联想测验(Go/No-go Association Task,GNAT)收集被试的行为数据(即d'和反应时),考查"部队群体一积极"与"非部队群体-积极"、"部队群体-消极"以及"非部队群体-消极"之间的d'和反应时是否存在显著差异.结果:GNAT感受性指标上,任务条件的主效应显著,F(3,117)=20.15,P<0.01.反应时指标上,任务条件的主效应显著,F(3,117)=19.70,P<0.01."非部队群体-积极"与"非部队群体-消极"之间的感受性指标与反应时上均不存在显著差异.结论:士兵群体中存在内隐集体自尊效应,内隐集体自尊并不是以贬低外群体为条件的.     

Acute alcohol decreases performance of an instrumental response to avoid aversive consequences in social drinkers

Background  Recent studies demonstrated that alcohol impairs inhibitory control of behavioural responses. Aims  We questioned whether alcohol via its disinhibiting effects would also impair the inhibition of an instrumental avoidance response in the presence of a safety signal. Design  Thirty-six moderate social drinkers were randomly allocated to receiving either alcohol (0.8 g/kg) or placebo before performing an instrumental avoidance procedure. White noise of 102 db was used as aversive outcome presented at a variable interval schedule in S+ trials, while no noise was presented in S− trials. An instrumental response (repeated space bar presses to avoid the noise presented at a variable interval) abolished the noise. The Stop Signal task and the affective Go/No-Go task were administered as inhibitory control tasks. Results  Alcohol did not change the avoidance response rate in the presence of S− (safety signal). However, participants under alcohol performed the avoidance response to a lower extent than placebo subjects in S+ trials. Alcohol impaired performance in the Stop Signal task and increased the number of commission errors in the affective Go/No-Go task. Conditioned attentional and emotional responses to the S+ as well as knowledge of stimulus–response outcome contingencies were not affected by alcohol. Conclusions  Acute alcohol may decrease the motivation to avoid negative consequences and thus might contribute to risky behaviour and binge drinking.     

Effects of inter-stimulus interval on skin conductance responses and event-related potentials in a Go/NoGo task

Skin conductance responses (SCRs) to NoGo stimuli have been found to be smaller than to Go stimuli, possibly due to their diminished task relevance. These findings have been obtained at inter-stimulus intervals (ISI) that were unusually short for SCR recordings. Therefore, we tested whether the same findings would also hold at longer ISIs. Simultaneously, effects of ISI duration on the NoGo-N2 and-P3 components of event-related brain potentials (ERPs) were assessed. Go and NoGo stimuli were equiprobable while ISI varied between 2, 5, and 8 s. Although increasing the ISI-enhanced SCR amplitudes in general, it did not modulate the attenuation of the response to NoGo relative to Go stimuli. When considered as difference between NoGo and Go conditions, neither the NoGo-N2 nor the NoGo-P3 was affected by ISI variation. Together, these data confirm the feasibility of co-registering ERPs and SCRs.     

Negative BOLD effect on somato-motor inhibitory processing: An fMRI study

Inhibiting inappropriate behavior and thoughts in the current context is an essential ability for humans, but the neural mechanisms for response inhibitory processing are a matter of continuous debate. The aim of this event-related functional magnetic resonance imaging (fMRI) study was to evaluate the negative blood oxygen level dependent (BOLD) effect on inhibitory processing during go/no-go paradigms. Fifteen subjects performed two different types of somatosensory go/no-go paradigm: (1) button press and (2) count. Go and no-go stimuli were presented with an even probability. We observed a common negative activation during Movement No-go and Count No-go trials in the right SFG, corresponding to BA 8. These findings suggest that the right SFG region was responsible for the negative BOLD effect on inhibitory processing, which was independent of the required response mode. We hypothesized several possible explanations for the deactivation of the SFG during no-go trials.     

浅析医院建筑设计与施工中的5大问题

文章探讨了医院建筑设计与施工中常见的5大问题,内容包括设计理念、不同设计单位的优势整合、合同中常见易引起歧义的文字表述、对投标文件编制说明的审阅以及医技科室的供暖与制冷问题,这些问题既应该引起政府有关部门及建设决策者的思考,也应该使基层的设计人员和业主对这些问题有更深的认识。     

Potential related to no-go reaction in go/no-go hand movement with discrimination between tone stimuli of different frequencies in the monkey

Monkeys were trained for go/no-go reaction-time hand movement with discrimination between tone stimuli of different frequencies, and field potentials related to the discriminative movement were recorded with electrodes implanted in various cortical areas and analysed by averaging procedure. In the cortex of the dorsal bank of the principal sulcus, surface-negative, depth-positive (s-N, d-P) potentials were recorded specifically on the no-go trial. The same monkey was also examined for go/no-go reaction-time hand movement with color discrimination. In the same monkey, the potentials related to the no-go reaction on the auditory stimulus were recorded in the rostral part of the dorsal bank of the principal sulcus, whereas the s-N, d-P potentials on the no-go visual stimulus were observed in the caudal part of the same bank. It is suggested that the dorsal bank of the principal sulcus is essentially related to the integrative functions such as judgement not to move and suppression of motor execution, and that different loci in this cortical area are respectively active for the functions of different sensory modalities.